Unique in Greece, the Rotunda is a cylindrical building from the early 4th century AD. The mosaics inside are really impressive. The Rotunda is a massive circular structure, built in 306 AD, with a masonry core. Through its long history, it has gone through multiple periods of use and modification as a polytheist temple, a Christian basilica, a Muslim mosque, and a Christian church once again. A minaret is preserved from its use as a mosque, and ancient remains are exposed on its southern side. Some Greek publications claim it is the oldest Christian church in the world. These days, the Rotunda is primarily an archaeological site, where you can see some remaining Christian mosaics and feel the weight of history.

Once owned by Richard II of England, the castle is the city’s foremost landmark and oldest monument. The structure boasts more than 1,700 years of history and still serves as a military fortress today. Don't miss the Navy Museum inside!

The Maritime Museum is located on the First and Second Floors of Fort St John’s. The exhibits on the First Floor give an overview of the development of Dubrovnik maritime trade and shipbuilding from its very start to the fall of the Dubrovnik Republic. The exhibits on the Second Floor show the resurgence of maritime trade in Dubrovnik and on the Pelješac Peninsula during the 19th century, as well as the strength of Dubrovnik steamships up until World War II and afterwards.